// Author: David Qin
// E-mail: david@hereapp.cn
// Date: 2014-11-05

(function($){

    // a case insensitive jQuery :contains selector
    $.expr[":"].searchableSelectContains = $.expr.createPseudo(function(arg) {
      return function( elem ) {
        return $(elem).text().toUpperCase().indexOf(arg.toUpperCase()) >= 0;
      };
    });
  
    $.searchableSelect = function(element, options) {
      this.element = element;
      this.options = options || {};
      this.init();
  
      var _this = this;
  
      this.searchableElement.click(function(event){
        // event.stopPropagation();
        _this.show();
      }).on('keydown', function(event){
        if (event.which === 13 || event.which === 40 || event.which == 38){
          event.preventDefault();
          _this.show();
        }
      });
  
      $(document).on('click', null, function(event){
        if(_this.searchableElement.has($(event.target)).length === 0)
          _this.hide();
      });
  
      this.input.on('keydown', function(event){
        event.stopPropagation();
        if(event.which === 13){         //enter
          event.preventDefault();
          _this.selectCurrentHoverItem();
          _this.hide();
        } else if (event.which == 27) { //ese
          _this.hide();
        } else if (event.which == 40) { //down
          _this.hoverNextItem();
        } else if (event.which == 38) { //up
          _this.hoverPreviousItem();
        }
      }).on('keyup', function(event){
        if(event.which != 13 && event.which != 27 && event.which != 38 && event.which != 40)
          _this.filter();
      })
    }
  
    var $sS = $.searchableSelect;
  
    $sS.fn = $sS.prototype = {
      version: '0.0.1'
    };
  
    $sS.fn.extend = $sS.extend = $.extend;
  
    $sS.fn.extend({
      init: function(){
        var _this = this;
        this.element.hide();
  
        this.searchableElement = $('<div tabindex="0" class="searchable-select"></div>');
        this.holder = $('<div class="searchable-select-holder"></div>');
        this.dropdown = $('<div class="searchable-select-dropdown searchable-select-hide"></div>');
        this.input = $('<input type="text" class="searchable-select-input" />');
        this.items = $('<div class="searchable-select-items"></div>');
        this.caret = $('<span class="searchable-select-caret"></span>');
  
        this.scrollPart = $('<div class="searchable-scroll"></div>');
        this.hasPrivious = $('<div class="searchable-has-privious">...</div>');
        this.hasNext = $('<div class="searchable-has-next">...</div>');
  
        this.hasNext.on('mouseenter', function(){
          _this.hasNextTimer = null;
  
          var f = function(){
            var scrollTop = _this.items.scrollTop();
            _this.items.scrollTop(scrollTop + 20);
            _this.hasNextTimer = setTimeout(f, 50);
          }
  
          f();
        }).on('mouseleave', function(event) {
          clearTimeout(_this.hasNextTimer);
        });
  
        this.hasPrivious.on('mouseenter', function(){
          _this.hasPriviousTimer = null;
  
          var f = function(){
            var scrollTop = _this.items.scrollTop();
            _this.items.scrollTop(scrollTop - 20);
            _this.hasPriviousTimer = setTimeout(f, 50);
          }
  
          f();
        }).on('mouseleave', function(event) {
          clearTimeout(_this.hasPriviousTimer);
        });
  
        this.dropdown.append(this.input);
        this.dropdown.append(this.scrollPart);
  
        this.scrollPart.append(this.hasPrivious);
        this.scrollPart.append(this.items);
        this.scrollPart.append(this.hasNext);
  
        this.searchableElement.append(this.caret);
        this.searchableElement.append(this.holder);
        this.searchableElement.append(this.dropdown);
        this.element.after(this.searchableElement);
  
        this.buildItems();
        this.setPriviousAndNextVisibility();
      },
  
      filter: function(){
        var text = this.input.val();
        this.items.find('.searchable-select-item').addClass('searchable-select-hide');
        this.items.find('.searchable-select-item:searchableSelectContains('+text+')').removeClass('searchable-select-hide');
        if(this.currentSelectedItem.hasClass('searchable-select-hide') && this.items.find('.searchable-select-item:not(.searchable-select-hide)').length > 0){
          this.hoverFirstNotHideItem();
        }
  
        this.setPriviousAndNextVisibility();
      },
  
      hoverFirstNotHideItem: function(){
        this.hoverItem(this.items.find('.searchable-select-item:not(.searchable-select-hide)').first());
      },
  
      selectCurrentHoverItem: function(){
        if(!this.currentHoverItem.hasClass('searchable-select-hide'))
          this.selectItem(this.currentHoverItem);
      },
  
      hoverPreviousItem: function(){
        if(!this.hasCurrentHoverItem())
          this.hoverFirstNotHideItem();
        else{
          var prevItem = this.currentHoverItem.prevAll('.searchable-select-item:not(.searchable-select-hide):first')
          if(prevItem.length > 0)
            this.hoverItem(prevItem);
        }
      },
  
      hoverNextItem: function(){
        if(!this.hasCurrentHoverItem())
          this.hoverFirstNotHideItem();
        else{
          var nextItem = this.currentHoverItem.nextAll('.searchable-select-item:not(.searchable-select-hide):first')
          if(nextItem.length > 0)
            this.hoverItem(nextItem);
        }
      },
  
      buildItems: function(){
        var _this = this;
        this.element.find('option').each(function(){
          var item = $('<div class="searchable-select-item" data-value="'+$(this).attr('value')+'">'+$(this).text()+'</div>');
  
          if(this.selected){
            _this.selectItem(item);
            _this.hoverItem(item);
          }
  
          item.on('mouseenter', function(){
            $(this).addClass('hover');
          }).on('mouseleave', function(){
            $(this).removeClass('hover');
          }).click(function(event){
            event.stopPropagation();
            _this.selectItem($(this));
            _this.hide();
          });
  
          _this.items.append(item);
        });
  
        this.items.on('scroll', function(){
          _this.setPriviousAndNextVisibility();
        })
      },
      show: function(){
        this.dropdown.removeClass('searchable-select-hide');
        this.input.focus();
        this.status = 'show';
        this.setPriviousAndNextVisibility();
      },
  
      hide: function(){
        if(!(this.status === 'show'))
          return;
  
        if(this.items.find(':not(.searchable-select-hide)').length === 0)
            this.input.val('');
        this.dropdown.addClass('searchable-select-hide');
        this.searchableElement.trigger('focus');
        this.status = 'hide';
      },
  
      hasCurrentSelectedItem: function(){
        return this.currentSelectedItem && this.currentSelectedItem.length > 0;
      },
  
      selectItem: function(item){
        if(this.hasCurrentSelectedItem())
          this.currentSelectedItem.removeClass('selected');
  
        this.currentSelectedItem = item;
        item.addClass('selected');
  
        this.hoverItem(item);
  
        this.holder.text(item.text());
        var value = item.data('value');
        this.holder.data('value', value);
        this.element.val(value);
  
        if(this.options.afterSelectItem){
          this.options.afterSelectItem.apply(this);
        }
      },
  
      hasCurrentHoverItem: function(){
        return this.currentHoverItem && this.currentHoverItem.length > 0;
      },
  
      hoverItem: function(item){
        if(this.hasCurrentHoverItem())
          this.currentHoverItem.removeClass('hover');
  
        if(item.outerHeight() + item.position().top > this.items.height())
          this.items.scrollTop(this.items.scrollTop() + item.outerHeight() + item.position().top - this.items.height());
        else if(item.position().top < 0)
          this.items.scrollTop(this.items.scrollTop() + item.position().top);
  
        this.currentHoverItem = item;
        item.addClass('hover');
      },
  
      setPriviousAndNextVisibility: function(){
        if(this.items.scrollTop() === 0){
          this.hasPrivious.addClass('searchable-select-hide');
          this.scrollPart.removeClass('has-privious');
        } else {
          this.hasPrivious.removeClass('searchable-select-hide');
          this.scrollPart.addClass('has-privious');
        }
  
        if(this.items.scrollTop() + this.items.innerHeight() >= this.items[0].scrollHeight){
          this.hasNext.addClass('searchable-select-hide');
          this.scrollPart.removeClass('has-next');
        } else {
          this.hasNext.removeClass('searchable-select-hide');
          this.scrollPart.addClass('has-next');
        }
      }
    });
  
    $.fn.searchableSelect = function(options){
      this.each(function(){
        var sS = new $sS($(this), options);
      });
  
      return this;
    };
  
  })(jQuery);